Grasshopper Mouse

The grasshopper mouse, belonging to the genus Onychomys, is a fascinating creature known for its unique behaviors and adaptations. Here’s a detailed overview of its natural history:

Physical Description

  • Size: Small rodents, typically around 4 to 5 inches in body length, with an additional 1 to 2 inches of tail.
  • Appearance: They have a robust body, short tails, and large ears. Their fur is generally grayish-brown on the back and white on the belly.


  • Geographic Range: Found in North America, particularly in the arid and semi-arid regions of the western United States and Mexico.
  • Preferred Environment: Grasshopper mice inhabit deserts, scrublands, and prairies. They are well-adapted to dry environments and can be found in areas with sparse vegetation.


  • Nocturnal Lifestyle: These mice are primarily nocturnal, coming out to hunt and forage at night.
  • Territoriality: Grasshopper mice are highly territorial and aggressive. They establish and defend territories vigorously.


  • Carnivorous Diet: Unlike many other rodents, grasshopper mice are primarily carnivorous. They feed on insects, other small invertebrates, and even small vertebrates.
  • Specialization: They are named for their tendency to prey on grasshoppers, but their diet can also include beetles, scorpions, spiders, and even other mice.
  • Hunting: Known for their hunting prowess, they are sometimes called “scorpion mice” due to their ability to hunt and consume scorpions, showing resistance to the venom.


  • Unique Calls: Grasshopper mice are known for their high-pitched, wolf-like howls, which they use to communicate with each other, especially to mark territory.


  • Breeding Season: Typically breed from spring through late summer.
  • Litter Size: Females give birth to 2 to 6 young after a gestation period of about 30 days.
  • Parental Care: The young are weaned after a few weeks and reach maturity at around 2 to 3 months.


  • Water Conservation: Adapted to arid environments, grasshopper mice obtain most of their water from the food they eat and have efficient kidneys to conserve water.
  • Venom Resistance: They have developed a resistance to the venom of scorpions, allowing them to prey on these arachnids without harm.

Ecological Role

  • Predator Control: By preying on insects and other small animals, grasshopper mice help control the populations of these species in their habitats.
  • Indicator Species: Their presence and health can be indicators of the ecological balance in their environment.

The grasshopper mouse’s unique dietary habits, vocalizations, and behaviors make it a remarkable example of adaptation to harsh environments, playing a crucial role in the ecosystems they inhabit.

Parietal Eye

The parietal eye, also known as the third eye, is a part of the pineal gland and is found in some species of reptiles and amphibians. It is a photosensitive organ located on the top of the head and is capable of detecting light and dark. Here are some key points about the parietal eye:

  1. Location and Structure: The parietal eye is situated in the parietal area of the brain, on the top of the head, and it is visible as a small, light-sensitive spot in some reptiles and amphibians.
  2. Function: The parietal eye’s primary function is to detect changes in light intensity, helping the animal regulate its circadian rhythms and hormone production. It can also influence basking, thermoregulation, and seasonal reproduction.
  3. Presence in Species: The parietal eye is found in various species of reptiles, such as some lizards (like iguanas) and tuataras, as well as some species of amphibians and fish. It is not present in birds or mammals.
  4. Evolutionary Aspect: The parietal eye is considered an ancient feature in vertebrate evolution, reflecting an early adaptation to environmental light changes.
  5. Comparison with Pineal Gland: While the parietal eye is light-sensitive, the pineal gland in other vertebrates (including humans) receives light information indirectly through the eyes and the brain. Both structures are involved in regulating circadian rhythms and reproductive cycles.

In summary, the parietal eye is an intriguing evolutionary feature that aids certain reptiles and amphibians in detecting environmental light and regulating physiological functions.

The Parietal Eye: Nature’s Light Sensor

The parietal eye, often called the third eye, is a fascinating feature found in some reptiles and amphibians. This photosensitive organ, located on the top of the head, plays a crucial role in detecting light and dark and aids in regulating various physiological processes.

Structure and Location

The parietal eye is situated in the parietal area of the brain and is visible as a small, light-sensitive spot. Unlike the primary eyes, which detect images, it acts as a direct light sensor. This organ is found in certain lizards (including iguanas), tuataras, and some amphibians and fish. Birds and mammals, however, do not possess this feature.

Function and Role

The primary function of the parietal eye is to detect changes in light intensity, helping the animal maintain its circadian rhythms and regulate hormone production. This detection influences behaviors such as basking, thermoregulation, and seasonal reproduction. By sensing light, the parietal eye helps these animals adapt to their environment, optimizing their physiological and behavioral responses.

Evolutionary Significance

The presence of the parietal eye is an ancient adaptation, reflecting early vertebrate evolution. It showcases how animals have developed specialized organs to respond to environmental changes. While the parietal eye is a direct light sensor, other vertebrates, including humans, rely on the pineal gland for similar functions. The pineal gland receives light information indirectly through the eyes and brain, playing a key role in regulating circadian rhythms and reproductive cycles.


The parietal eye is a remarkable evolutionary feature that underscores the diversity of adaptations in the animal kingdom. By detecting light and dark, it enables reptiles and amphibians to finely tune their behaviors and physiological processes to their environments, ensuring their survival and reproductive success.


The parietal eye, or third eye, is a light-sensitive organ found in some reptiles and amphibians, situated on the top of the head. It detects changes in light intensity, aiding in regulating circadian rhythms, hormone production, and behaviors like basking and thermoregulation. Present in species such as lizards, tuataras, and some amphibians, this ancient adaptation highlights early vertebrate evolution. Unlike the parietal eye, the pineal gland in other vertebrates receives light information indirectly through the eyes and brain. This unique feature helps these animals optimize their responses to environmental changes, ensuring survival and reproductive success.

Western Fence lizards are out at Tin Can Point

This turquoise colored fence lizard (Sceloporus occidentalis) was seen out in the warmth of early Spring at Tin Can Point. Tin Can Point is just up from Fern Lodge Junction on the Gabrielino Trail. It’s the first switchback you’d encounter after the trail passes through the canyon live oak forest and then enters the chaparral, just a few minutes up from the trail junction.

A beautiful fence lizard basks in the gentle warmth of early Spring at Tin Can Point.   See inset of the Chantry Flat – Mt. Wilson Trails map, below, to see where this point is.  As of this writing,  a cold wet pacific storm is dropping nearly six days of chilly rain and snow in much of the San Gabriel mountains.  Big Santa Anita Canyon dam has received over 5 1/2″ of rain in the last week.  Something I just learned recently about these Western Fence lizards is that their populations have the effect of reducing the incidence of Lyme’s disease in the ticks that live in the chaparral,  such as found covering much of the slopes of the Big Santa Anita Canyon!  Apparently, a protein in the lizard’s blood kills the bacterium in the tick’s gut, which is good news for hikers and even their dogs during the spring and autumn months.

Like most reptiles, Western Fence lizards hibernate, at least for a little while each winter throughout their habitats which are wide-spread throughout California.  As for food, these lizards eat spiders and various insects such as mosquitos, beetles and grasshoppers.   The females lay several small clutches of eggs (3-17) in the spring, the young emerging in the summer.

Detail of Gabrielino Trail section, Chantry Flat – Mt. Wilson Trails map.

On your next hike out from Chantry Flats, watch for for lizards flitting about on the trails and sunning themselves on the myriad stretches of rock.  As for the various types of reptiles to be found in the Big Santa Anita, Western Fence lizards are abundant and deserve a place in the sun!

source:  Wikipedia, Western Fence lizards

Loggerhead Shrike


The Loggerhead Shrike, scientifically known as Lanius ludovicianus, is a fascinating and unique bird species, notable for its predatory habits despite its small size. It belongs to the shrike family, which is known for its members’ unusual behavior of impaling their prey on thorns, twigs, or barbed wire. This distinctive behavior has earned them the nickname “butcher birds.”

loggerhead shrike


  • Size and Appearance: The Loggerhead Shrike is a medium-sized bird measuring about 8 to 9 inches long. It has a distinctive black mask that extends across its eyes and forehead, a grey back, and a white underbelly. Its wings are black with white patches, and it has a relatively large head compared to its body size, which is where its name “loggerhead” comes from.
  • Diet: This bird is carnivorous, feeding on various prey, including insects, small mammals, birds, and reptiles. It lacks the strong talons of raptors, so it uses its hooked beak to kill and manipulate its prey.
  • Habitat: Loggerhead Shrikes are found across North America, particularly in open habitats such as grasslands, farmlands, and desert edges. They require environments with suitable perches for hunting and dense vegetation or other structures for impaling their prey.
  • Reproduction: They are monogamous birds that nest in trees or shrubs. The female typically lays 4 to 8 eggs, which both parents help to incubate. After hatching, the young are fed by both parents until they are ready to fledge.

Conservation Status

The Loggerhead Shrike is considered a species of conservation concern in many parts of its range due to habitat loss, pesticide use, and collisions with vehicles. Efforts are being made to monitor populations and conserve their habitats to help stabilize and increase their numbers.

Despite their fierce hunting habits, these birds play an important role in their ecosystems by controlling insect and small vertebrate populations. Understanding and conserving the Loggerhead Shrike and its habitat is vital for maintaining the balance of ecosystems where these unique birds live.

OpenAI. (2024). ChatGPT (4) [Large language model].

Mojave Desert Wildlife by Diet


The Mojave Desert, located in the southwestern United States, is home to diverse wildlife adapted to the harsh desert conditions. Here’s a breakdown of Mojave Desert wildlife based on their diets:

  1. Herbivores:
    • Desert Bighorn Sheep: Grazes on various desert plants, including grasses, shrubs, and forbs.
    • Antelope Ground Squirrel: Feeds on seeds, fruits, and vegetation.
    • Desert Tortoise: Primarily herbivorous, consuming various plants such as cacti, grasses, and herbs.
  2. Carnivores:
    • Kit Fox: Hunts small mammals, birds, and insects.
    • Coyotes: Opportunistic omnivores, consuming small mammals, birds, and plants.
    • Bobcat: Preys on rabbits, rodents, birds, and occasionally larger mammals.
    • Sidewinder Snake: Feeds on small rodents and lizards.
  3. Omnivores:
    • Black-tailed Jackrabbit: Primarily herbivorous but may consume insects and other small animals.
    • Gila Monster: Feeds on small mammals, birds, eggs, and occasionally plant material.
    • Roadrunner: Eats insects, small reptiles, and even snakes.
  4. Insectivores:
    • Desert Iguana: Consumes a mix of insects, flowers, and leaves.
    • Horned Lizard: Feeds primarily on ants and other small insects.
    • Solifuge (Sun Spider): Carnivorous, preying on insects and other small arthropods.
  5. Scavengers:
    • Turkey Vulture: Feeds on carrion, crucial in cleaning up the desert ecosystem.
    • Common Raven: Opportunistic scavenger, feeding on carrion and various food sources.
  6. Specialized Feeders:
    • Joshua Tree Yucca Moth: Larvae feed on Joshua tree seeds, and adult moths pollinate the Joshua tree flowers.
    • Harvester Ants: Collect and store seeds as a primary food source.
  7. Nectar Feeders:
    • White-winged Dove: Consumes seeds and fruits but also feeds on nectar from desert flowers.
    • Anna’s Hummingbird: Feeds on nectar from desert flowers, contributing to pollination.

These are just a few examples, and the Mojave Desert supports a wide range of other species with diverse dietary preferences. The ability of these animals to find food and water in an environment with limited resources is a testament to their remarkable adaptations to desert life.

Desert Food Chain

The desert food chain is a complex system involving various organisms interacting for energy and survival. Despite the harsh conditions of deserts, life has adapted to these environments, and a delicate balance exists within the food chain. Here is a simplified overview of the desert food chain:

  1. Producers:
    • Plants and Cacti: Deserts have specialized plants adapted to conserve water and thrive in arid conditions. Examples include cacti, succulents, and drought-resistant shrubs. These plants are primary producers, converting sunlight into energy through photosynthesis.
  2. Primary Consumers:
    • Herbivores: Insects, rodents, and small mammals feed on desert plants. Examples include grasshoppers, mice, and rabbits. These organisms are primary consumers that obtain their energy by consuming plants.
  3. Secondary Consumers:
    • Carnivores: Predators in the desert feed on herbivores. Examples include snakes, lizards, and birds of prey. Some mammals like foxes and coyotes also fall into this category, preying on smaller animals for sustenance.
  4. Tertiary Consumers:
    • Top Predators: Larger predators at the top of the desert food chain prey on herbivores and smaller carnivores. Examples include large birds of prey like eagles and apex predators like some species of big cats (e.g., cougars or cheetahs, depending on the desert region).
  5. Scavengers:
    • Scavengers: These organisms feed on the remains of dead animals. Scavengers play a crucial role in nutrient recycling in the desert ecosystem. Examples include vultures, hyenas, and certain types of beetles.
  6. Decomposers:
    • Microorganisms: Decomposers decompose organic matter, such as dead plants and animals, into simpler nutrients the soil can absorb. Bacteria and fungi are essential decomposers in the desert ecosystem.

Throughout this food chain, energy is transferred from one trophic level to the next, with each level being dependent on the level below for its energy source. Water is a limiting factor in deserts, and many organisms have adapted various mechanisms to conserve water or extract it efficiently from their food sources. The delicate balance of the desert food chain is essential for the survival of its inhabitants in these harsh environments.

Tarantula Migration

The term “tarantula migration” is often used to describe the phenomenon of large groups of tarantulas moving en masse in search of food, mates, or new habitats. Tarantulas are solitary spiders for most of the year, but during certain seasons, they may engage in these migrations. This behavior is more commonly observed in some species of tarantulas, particularly in the southwestern United States.

Here are some key points about tarantula migrations:

Timing: Tarantula migrations typically occur in the late summer and early fall, often in August and September. This timing is associated with the mating season for many tarantula species.

Purpose: Tarantulas migrate to find mates as males search for females. The females may also move to find suitable locations to lay their eggs or search for prey.

Location: The most famous tarantula migrations in the United States occur in the deserts of the American Southwest, such as Arizona and California. These migrations can involve thousands of tarantulas moving across the desert floor.

Behavior: During a migration, tarantulas can be seen traveling on the ground in search of food and potential mates. They often move during the evening and nighttime to avoid extreme daytime heat.

Species: The most well-known species that participate in these migrations is the Aphonopelma species, commonly called the desert tarantula. However, not all tarantulas engage in migrations, and the behavior can vary among different species.

Conservation: Tarantula migrations are an important part of the ecosystem, as they help control insect populations and serve as a food source for various predators. Conservation efforts are often aimed at protecting their habitats.

During a tarantula migration, it’s not uncommon for people to go out and observe or photograph the spiders. Still, it’s essential to do so responsibly and without disturbing their natural behavior or habitats.

Suppose you’re interested in witnessing a tarantula migration. In that case, it’s best to consult local experts or naturalists who can guide you to appropriate locations and provide you with additional information on when and where to observe this fascinating natural phenomenon.

Tarantulas Mating Process


The mating process of tarantulas, like many other spiders, is quite fascinating and can vary among different species, but there are some common elements to it. Here’s a general overview of how tarantulas mate:

Courtship: The process typically begins with a male tarantula searching for a receptive female. Male tarantulas are often smaller and have less colorful markings than females. When a male finds a female’s silk-lined burrow or web, he approaches cautiously to initiate courtship. However, approaching a female can be risky because some females may perceive the male as potential prey rather than a potential mate.

Drumming and vibrations: To signal his intentions to the female, the male may engage in courtship rituals, including drumming on the female’s web or tapping on her burrow. These vibrations are thought to be a way for the male to communicate and let the female know he is not a threat.

Presentation of a sperm sac: Once the male has successfully courted the female, he may present her with a sperm sac. This sac contains sperm that he has produced and stored in his pedipalps, which are modified appendages near the front of his body.

Copulation: If the female is receptive to the male’s advances, she will allow him to approach her. They engage in a mating ritual in which the male transfers his sperm into the female’s reproductive organs using specialized structures called pedipalps. This process can be risky for the male, as the female might suddenly become aggressive or attempt to prey on him.

Male retreats: After copulation, the male usually makes a hasty retreat to avoid being attacked by the female. Some male tarantulas may not survive this encounter, especially in species with highly aggressive females.

Female’s egg sac: If the mating is successful, the female will eventually lay eggs and create an egg sac, which she guards closely. The female may carry the egg sac with her and continue to protect it until the spiderlings (baby tarantulas) hatch.

It’s important to note that the mating process in tarantulas can be dangerous for the males, as females of some species are known to be aggressive and may cannibalize the male after mating. To maximize their chances of reproducing, male tarantulas have developed various courtship behaviors and tactics to minimize the risk of being consumed.

Additionally, the mating process can vary between different tarantula species, and some species may have unique courtship rituals and behaviors.

Tarantula Hawk Wasp


The tarantula hawk wasp is a large and impressive species of wasp known for its distinctive and painful sting. These wasps are primarily found in the southwestern United States, Mexico, and parts of Central and South America. Here are some key characteristics and facts about the tarantula hawk wasp:

Size: Tarantula hawk wasps are among the largest wasps in the world, with a body length that can reach up to 2 inches (5 cm).

Coloration: They are usually brightly colored, with black bodies and iridescent blue or black wings. The coloration may vary among species.

Venomous sting: Tarantula hawk wasps are solitary predators, and their primary prey is tarantulas. They paralyze the tarantula with their potent venomous sting, then lay an egg on the immobilized spider. The larva that hatches from the egg feeds on the paralyzed tarantula.

Painful sting: The sting of a female tarantula hawk is considered one of the most painful insect stings in the world, and it is rated as a 4 on the Schmidt Sting Pain Index, created by entomologist Justin Schmidt. The pain from the sting can be excruciating and may last for several minutes.

Solitary behavior: Tarantula hawk wasps are solitary insects, meaning they do not form colonies or nests like social wasps such as yellow jackets or paper wasps. Each female hunts for and provisions her own prey.

Males vs. females: Male tarantula hawk wasps are typically smaller than females and do not have a stinger. Their primary purpose is to mate with females.

Habitat: These wasps are often found in arid or desert regions, where tarantulas are more abundant. They are also commonly spotted near flowers, as they feed on nectar and other plant fluids in addition to hunting for tarantulas.

Flight: Tarantula hawk wasps are known for their agile and powerful flight. They can be seen soaring through the air in search of tarantulas or nectar-rich flowers.

Defensive behavior: Although tarantula hawk wasps are not typically aggressive toward humans, they will defend themselves if they feel threatened. It’s best to observe them from a safe distance to avoid getting stung.

Conservation: These wasps play a role in regulating tarantula populations, and they are considered beneficial in their ecosystems. However, they are vulnerable to habitat loss and pesticides, which can impact their populations.

In summary, the tarantula hawk wasp is a fascinating and somewhat intimidating insect known for its painful sting and unique predatory behavior. While they can deliver a formidable sting, they are generally not aggressive toward humans unless provoked.


Chukars (Alectoris chukar) were introduced to the Mojave Desert in the southwestern United States in the mid-20th century. These introductions were part of efforts to establish populations of chukars for hunting and recreational purposes in the arid regions of the United States. Chukars were brought to the Mojave Desert and other arid areas in the western United States as game birds to provide opportunities for hunters.

The specific dates of these introductions can vary by location, but chukars were likely introduced to the Mojave Desert in the 1940s and 1950s. The birds adapted well to the desert environment and have since established populations in parts of the Mojave Desert, making them a popular game bird for hunting in the region. However, it’s worth noting that their introduction has led to both positive and negative ecological impacts, and they are a subject of interest and concern in terms of their effects on native flora and fauna.

The chukar (Alectoris chukar) is a bird species that belongs to the partridge family and is native to the rocky and hilly regions of South Asia and parts of the Middle East. Chukars have been introduced to various other regions for hunting and have established populations in some parts of the world. Here are some key characteristics and information about chukars:

  1. Physical Description: Chukars are medium-sized game birds with a plump body and relatively short legs. They have distinctive markings, including a barred pattern on their flanks and a black line running from their beak, through the eye, and down the side of the neck. Males and females are similar in appearance, but males tend to have slightly brighter and more vibrant colors.
  2. Range: Chukars are native to various habitats across South Asia, including countries like Pakistan, India, Nepal, and parts of the Middle East, including Iran and Turkey. They have also been introduced to other parts of the world, including North America, New Zealand, and some European countries, as game birds.
  3. Habitat: Chukars prefer arid and rocky habitats like desert canyons, hillsides, and semi-arid landscapes. They are well adapted to living in rugged terrain and can be found at various elevations, from low deserts to high mountains.
  4. Behavior: Chukars are social birds and often gather in coveys, which are groups of individuals. They feed on a variety of seeds, plants, and small insects. Their call is distinctive and sounds like “chukar-chukar-chukar,” which is how they got their common name.
  5. Reproduction: Chukars typically nest in rocky crevices or depressions on the ground. The female incubates the eggs, and the chicks are precocial, meaning they can leave the nest shortly after hatching. Chukar chicks can feed themselves and are raised by the female until they are old enough to fly.
  6. Conservation: Chukars are not considered globally threatened, and their populations are stable in their native range. However, in regions where they have been introduced as game birds, they are subject to hunting regulations to ensure sustainable populations.
  7. Game Birds: Chukars are popular game birds, and they are commonly hunted for sport and their meat. They are often released for hunting purposes in many parts of the world.

Chukars are known for their adaptability to arid and rocky environments and are appreciated by hunters for their challenging behavior and flight patterns. They have become established in various regions due to their introduction to recreational hunting.